22 research outputs found
Generalized vector valued almost periodic and ergodic distributions
For \Cal A\subset L^1_{loc}(\Bbb J,X) let \Cal M\Cal A consist of all
with M_h f (\cdot):=\frac {1}{h}\int_{0}^{h}f(\cdot +s)\,ds
\in \Cal A for all . Here is a Banach space, or . Usually \Cal A\subset\Cal M\Cal
A\subset \Cal M^2\Cal A\subset ....
The map \Cal A \to \Cal {D}'_{\Cal A} is iteration complete, that is
\Cal {D}'_{\Cal {D}'_{\Cal A}}= \Cal {D}'_{\Cal A}. Under suitable assumptions
\widetilde {\Cal M}^n \Cal {A}= \Cal A + \{T^{(n)} : T \in \Cal A\}, and
similarly for \Cal {M}^n \Cal A. Almost periodic -valued distributions
\h'_{\A} with \A = almost periodic (ap) functions are characterized in
several ways.
Various generalizations of the Bohl-Bohr-Kadets theorem on the almost
periodicity of the indefinite integral of an ap or almost automorphic function
are obtained.
On \Cal {D}'_{\Cal E} , \Cal E the class of ergodic functions, a mean
can be constructed which gives Fourier series. Special cases of \Cal A are
the Bohr ap, Stepanoff ap, almost automorphic, asymptotically ap, Eberlein
weakly ap, pseudo ap and (totally) ergodic functions (\T)\E.
Then always \Cal {M}^n \Cal A is strictly contained in \Cal {M}^{n+1}
\Cal A. The relations between \m^n \E, \m^n\T\E and subclasses are
discussed. For many of the above results a new -condition is needed,
we show that it holds for most of the \A needed in applications.
Also, we obtain new tauberian theorems for to
belong to a class \A which are decisive in describing the asymptotic behavior
of unbounded solutions of many abstract differential-integral equations. This
generalizes various recent resultsComment: 69 page